*{.sh,run}: stderr_matches() wrapper calls: removed no longer needed prep_try/rethrow

lib/sh/util.sh: stderr_matches(): moved prep_try/rethrow into the function itself so that callers don't have to wrap this function in a complex sequence of prep_try/rethrow statements

lib/sh/util.sh: added rethrow_exit alias

fix: lib/sh/db.sh: pg_table_exists(): use stderr_matches() rather than just the exit status. this also avoids highlighting the benign error.

fix: lib/sh/db.sh: pg_table_exists(): use stderr_matches() rather than just the exit status. this also avoids highlighting the benign error.

fix: inputs/input.Makefile: removed no longer used special handling of XML inputs, support for which was never added to the Makefile. (bin/map, however, does support importing an XML file into a database.) this fixes a bug in XAL, which used to abort with an error but now just imports an empty table.

fix: inputs/input.Makefile: %/install: don't ignore errors if table does not exist, to ensure a proper errexit. this is now possible because every dir that this target is being run on should be a data dir. (Source/ used to be a metadata-only dir.)

bugfix: inputs/input.Makefile: $(cleanup): need `set -o pipefail`

inputs/VegBank/run: `rm=1 import()`: updated runtime (1 h)

inputs/VegBank/taxon_observation.**/test.xml.ref: updated inserted row count